It is a full-bodied wine with a bouquet redolent of moldy peaches and a finish that can evoke everything from all-purpose bathroom cleaner to uric acid.

In prisons, it is known as pruno -- cellblock wine made from fruit, sugar and mess-hall punch. It is potent, easy to brew and has been around for ages.

But officials at Los Angeles County's only state prison have come up with a plan to make pruno as rare as a 1945 Chateau Latour Bordeaux.

In October, the maximum-security lockup in Lancaster removed fresh fruit -- the preferred base for pruno -- from the boxed lunches delivered daily to the cells of its 4,000 inmates.

The goal, prison spokesman Lt. Ron Nipper said, is to reduce violent incidents at the institution. In the first nine months of the year, 102 assaults on staff and 122 violent incidents between inmates were reported.

"With a lot of our serious incidents, the inmates are drunk," Nipper said. "We've got to put a serious damper on making alcohol."

The crackdown is not only an attempt to make the prison safer but also part of a push by the state Department of Corrections to make prisoners healthier and reduce long-term medical costs. Since 1999, the state's 33 prisons have been phasing in standardized "heart healthy" menus that feature balanced meals,

low-fat foods and fresh fruit.

But this year, California wardens were asked to crack down on pruno, arguing that dietary health gains are nullified when prisoners consistently get drunk and turn violent.

The move is also part of a broader campaign to treat inmates with substance- abuse problems. About 85 percent of the state's 160,000 inmates were addicted to drugs or alcohol when they committed their crimes, state corrections spokesman Russ Heimerich said.

"The idea is to get them free of what they're addicted to," Heimerich said. "And people who are clearheaded are more likely to make more rational choices - - including whether to commit violent acts."

State corrections officials are considering taking the fresh fruit ban systemwide. Prisons already are prohibited from serving three popular pruno ingredients -- oranges, raisins and sugar packets. But a state report determined that creative prisoners can make pruno from yams, flavored gelatin, honey, hard candies -- anything with sugars that can be converted into alcohol in the fermentation process.

"You can make (pruno) out of ketchup," Heimerich said. "Some inmates were even using the frosting off of cakes. It's pretty much an unwinnable battle."

Lancaster prison officials say it's too early to tell whether the new regulation is having a direct effect on pruno production. Because of a number of recent violent incidents, some of the yards have remained locked down for months, which means that for now, some prisoners receive all meals in their cells.

Corrections officers concede that it will be difficult to stop pruno production. The basic recipes are simple and require only a rudimentary knowledge of the fermentation process, in which sugars are broken down into ethyl alcohol and carbon dioxide in the presence of yeast.

San Quentin death row inmate Jarvis Masters calls for fruit cocktail, oranges, white sugar and ketchup in his 1992 poem "Recipe for Prison Pruno," which won a PEN award.

Most prison brewers let the ingredients ferment in a plastic bag, then share the potent results with cellmates who have contributed their fruit to the mix. The end result, by most accounts, is best gulped quickly while holding one's nose.

Los Angeles County Sheriff's Capt. Rick Adams, who heads the Men's Central Jail in downtown Los Angeles, said pruno is a bigger problem than drugs at the 6,800-inmate facility.

The most famous recipe for jailhouse pruno comes from Jarvis Masters, a death row inmate at San Quentin who won a PEN Award for his 1992 poem "Recipe for Prison Pruno."

Take orange peels, fruit cocktail and water and heat it for 15 minutes in your sink with hot water. Keep mixture warm with towels for fermentation. Leave hidden and undisturbed for two days. Add sugar cubes and 6 teaspoons of ketchup. Heat for 30 minutes. Wrap and leave undisturbed for three more days. Reheat daily for 15 minutes for three more days. Skim and Serve.